Road bike sprocket teeth question more or less
Discussion
Im going to start using my road again now to loose some of this xmas weight.
The problem i had with it last year was on downhill sections in top gear my legs would be going like the clappers and I wouldn't be propelling the bike.
To sort this out can I just get a bigger front sprocket and or bigger/more teeth on the final gear of the rear cassette?
The problem i had with it last year was on downhill sections in top gear my legs would be going like the clappers and I wouldn't be propelling the bike.
To sort this out can I just get a bigger front sprocket and or bigger/more teeth on the final gear of the rear cassette?
so for pedaling down hill so my legs arent going around so fast and the pedal force feels like there is some resistance i need less teeth on the top gear rear cassette sprocket?
so for example say the chain had 100 holes and the sprocket had 25 teeth it would take me 4 revolutions of the pedal for 1 revolution of the wheel.
If i had 20 teeth i would need to pedal 5 times
What sort of sprocket do most people use?
I will count my sprocket teeth tongight buty i think i have like a 32 tooth
so for example say the chain had 100 holes and the sprocket had 25 teeth it would take me 4 revolutions of the pedal for 1 revolution of the wheel.
If i had 20 teeth i would need to pedal 5 times
What sort of sprocket do most people use?
I will count my sprocket teeth tongight buty i think i have like a 32 tooth
No
It's the ratio of the number of teeth on the front chainring and the rear sprocket. If the front chainring is 44 teeth and the rear sprocket is 11 teeth you'll do 4 revolutions of the rear wheel for every revolution of the chainring.
Easy riding: Small front chainring and big rear sprocket. i.e. 22 front and 32 rear means you'll do approx 1.5 chainring revolutions per rear wheel revolution
Hard riding: Big front chainring and small rear sprocket. i.e. 42 front and 11 rear means you'll do approx .25 chainring revolutions per rear wheel revolution
Road bikes are likely to have 50(ish) at the front and 11 at the rear. If you're descending and can't pedal fast enough to keep up with the bike you're probably doing about 40 mph.
It's the ratio of the number of teeth on the front chainring and the rear sprocket. If the front chainring is 44 teeth and the rear sprocket is 11 teeth you'll do 4 revolutions of the rear wheel for every revolution of the chainring.
Easy riding: Small front chainring and big rear sprocket. i.e. 22 front and 32 rear means you'll do approx 1.5 chainring revolutions per rear wheel revolution
Hard riding: Big front chainring and small rear sprocket. i.e. 42 front and 11 rear means you'll do approx .25 chainring revolutions per rear wheel revolution
Road bikes are likely to have 50(ish) at the front and 11 at the rear. If you're descending and can't pedal fast enough to keep up with the bike you're probably doing about 40 mph.
plumAJP said:
I will count my sprocket teeth tongight buty i think i have like a 32 tooth
Sounds like you might be selecting the wrong gear - for maximum speed you should be in the smallest rear sprocket and the biggest front chainring. The size of the largest sprocket is irrelevant.If you're using that combo and still spinning out then either you're a mentalist on the descents, or you're a future world champion!
I tend to find that when I spin out on a descent, it's time to get as low as possible, and concentrate on the road.
If you're spinning out on 53 at the front, and 11 at the back, and still want to keep pedalling, I would suggest you must be on a very straight road, that is smoothly surfaced. Or a ski-jump with a death wish...?
If you're spinning out on 53 at the front, and 11 at the back, and still want to keep pedalling, I would suggest you must be on a very straight road, that is smoothly surfaced. Or a ski-jump with a death wish...?
Sorry guys. I do mean the higher gear so if that's the small ring on the cassette then that's the one I need to change.
It's only a cheapy bike 21 speed bike.
I will count the teeth and post it up in 10 mins
When I'm pedalling out I'm doing about 35ish mph on a slight decline it's a slight bend too so I can't be going too fast or be world champ
It's only a cheapy bike 21 speed bike.
I will count the teeth and post it up in 10 mins
When I'm pedalling out I'm doing about 35ish mph on a slight decline it's a slight bend too so I can't be going too fast or be world champ
plumAJP said:
Sorry guys. I do mean the higher gear so if that's the small ring on the cassette then that's the one I need to change.
It's only a cheapy bike 21 speed bike.
I will count the teeth and post it up in 10 mins
When I'm pedalling out I'm doing about 35ish mph on a slight decline it's a slight bend too so I can't be going too fast or be world champ
A 21 speed will have a screw on 7 gear rear block, they're about 30-15 as standard and you'll have a massive effort trying to find anything smaller.It's only a cheapy bike 21 speed bike.
I will count the teeth and post it up in 10 mins
When I'm pedalling out I'm doing about 35ish mph on a slight decline it's a slight bend too so I can't be going too fast or be world champ
If you must get a bigger front chainring - on a 3x7 setup this will most likely mean replacing the cranks and will be quite expensive. However, if you want to get fit just pedal harder on the uphills and relax on the downs.
plumAJP said:
It has 48 or 49 teeth up front and 14 or 15 on the rear. Light is crap in garage now.
You should be able to get a rear block or cassette with less teeth on the smallest cog, if it is a screw on then you will be able to get one with 12 or 13 teeth; if it is a cassette then you will be able to get one with 11 teeth.Is it a road or a mountain bike that you have?
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